The present invention concerns a sealing valve, made from a rubber elastic material, for container openings having a stopper member which can be introduced into the opening of the container up to a stopper collar projecting in a radial direction beyond the stopper member, wherein at least one control channel is formed on the stopper member which extends in the longitudinal direction of the sealing valve from a lower side of the stopper member up to the stopper collar.
A sealing valve of this kind has become known in the art through DE 41 35 711 C2.
Storage battery cells require sealing valves which reliably prevent the escape of battery acid and H2 gas under normal pressure conditions and which open at a defined excess pressure within the battery cell to facilitate venting. Such storage batteries, in particular lead storage batteries for motor vehicles, are mass-produced articles whose sealing valves must be manufactured as economically as possible.
The control channel of the conventional sealing valve provides a defined flow path for fluids up to a sealing lip.
A defined pressure loading of this intended venting location is thereby possible. This leads to an improved, controllable and sensitive response.
AT-B-329 123 describes a sealing valve for storage batteries using another technique for venting the storage battery. In the assembled state, an annular gap is formed between a tubular connector and a stopper body. A vent opening connects the annular gap to the surroundings of the storage battery. The annular gap is subdivided into individual chambers connected to each other via passage openings so that electrolytic particles on the walls of the chambers can be precipitated and their escape prevented or curtailed.
The stopper collar of the conventional sealing valve disclosed in DE 41 35 711 C2 seats on an edge of the container along nearly the entire lower side of the collar. This extensive contact surface can lead to a sticking of the stopper collar to the edge of the container. This impairs the function of the conventional stopper-shaped sealing valve and causes irregularities in its response.
For this reason, the conventional sealing valve disclosed in DE 41 35 711 C2 is preferentially manufactured as a sealing cap, since, in this case, the sealing lip extends and seats in a sealing fashion about the periphery on the outer surface of the container, wherein the control channel ends at the sealing lip.
Problems occur during mass production of this conventional sealing cap disclosed in DE 41 35 711 C2. Separation of the sealing valve from the mould is difficult, since the sealing lip engages behind the mould and removal of the completed sealing valve from the mould is therefore problematic.
It is thereby the technical problem underlying the present invention to further improve the conventional sealing valve disclosed in DE 41 35 711 C2 in such a fashion that a reliable venting and sealing with respect to the escape of battery liquids is guaranteed while simultaneously facilitating economical production with high yield.
This problem is solved in accordance with the invention in that a sealing lip is formed on the stopper collar which can seat in a sealing fashion on a container edge surrounding the container opening, wherein the stopper collar has a control channel section which is transverse to the control channel of the stopper member to extend the control channel up to the sealing lip.
The sealing valve in accordance with the invention can be easily inserted into the opening of the container so that the sealing lip seats on the container edge. The stopper collar with the sealing lip formed thereon prevents the sealing valve from being inserted too far into the container opening. The sealing lip thereby seats on the edge of the container to guarantee good sealing of the inner region of the container. The extension of the longitudinal control channel in a radial direction leads to defined application of pressure at a certain location of the sealing lip. The defined flow guidance up to the sealing lip assures reproduceable venting of the inside of the container by the stopper-type sealing valve. Sticking and pressing of the stopper collar, which impairs its function, can be prevented.
The following parameters are important for defining the response of the sealing valve: The dimensions of the sealing lip at the stopper collar, the stiffness of the material, and the cross-sectional area of the control channel.
In a preferred embodiment, the sealing lip has at least one prominent sealing edge. The formation of a sealing edge reduces the sealing surface to a sealing line and results in a particularly precise, sensitive and well defined response to changes in pressure within the control channel. In addition, adhesive forces between the sealing edge and the sealing surface at the container edge, which could endanger a proper venting, can be avoided.
A plurality of sealing edges, positioned radially one behind the other, can also be provided to improve the reliability of the seal. A plurality of possible sealing edges also allows the sealing valve in accordance with the invention to be inserted into container openings with which the thickness of the wall of the container connector is subject to tolerance variations. At least one of the possible sealing edges can then seat on the edge of the container to facilitate operation of the sealing valve.
In an additional embodiment, a resilient element is disposed on the outer surface of the stopper member facing away from the container. The resilient element can compensate for tolerances between the sealing valve and a battery cover disposed above the sealing valve. The battery cover applies pressure to the resilient element so that the stopper member is pushed into the container opening to press the sealing lip onto the edge of the container. This bridges differing separations between the battery cover and the stopper member. The resilient element is preverentially disposed in the middle or symmetrically in a central fashion. The application of pressure to the resilient element in a longitudinal direction of the sealing valve allows for even transfer of forces onto the stopper member and the sealing lip. The opening and closing operation of the sealing valve is thereby more reproduceable.
In a first realization of this embodiment, the resilient element is made from a rubber elastic material and/or is formed integrally on the stopper member. Integration of the resilient element on the stopper member precludes need for a separate, external resilient element. The resilient element is present in the produced state and disposed at the optimum position for introduction of forces.
In a second embodiment, the resilient element can also be a helical spring dashed lines 42 of FIG. 2. In this case one can decide, in dependence on the separation between the battery cover and the stopper member, whether or not a separate resilient element (helical spring) should be used and which characteristics it should have. In this manner, the pressure loading of the sealing lip on the edge of the container can be individually adjusted to the application at hand.
In an additional variation of the invention, nubs 40 are provided on the outer peripheral surface of the stopper member. These nubs facilitate engagement and snapping into corresponding recesses 41 in the inner side of the container opening. The sealing valve is then held at a fixed position in the container opening. The nubs can, however, also be used to create a control channel to separate the outer peripheral surface of the stopper member from the inner side of the container opening.
In principle, all rubber elastic materials are suitable for production of the sealing valve in accordance with the invention. However, e.g. fluoroelastomers FPM, FKM as well as silicon rubber materials are preferred.
Further features and advantages of the invention can be derived from the subsequent description of an embodiment of the invention with regard to the drawing, showing details important to the invention, and from the claims. The features can be used in embodiments of the invention individually or collectively in arbitrary combination.